From c9a079914c1030734d55fb3b6aa1586cd3d4bf32 Mon Sep 17 00:00:00 2001
From: Avanish Singh <79073722+aaviix@users.noreply.github.com>
Date: Thu, 16 Nov 2023 16:19:05 +0100
Subject: [PATCH] serviceWorker.js
---
frontend-react/src/serviceWorker.js | 137 ++++++++++++++++++++++++++++
1 file changed, 137 insertions(+)
create mode 100644 frontend-react/src/serviceWorker.js
diff --git a/frontend-react/src/serviceWorker.js b/frontend-react/src/serviceWorker.js
new file mode 100644
index 0000000..1ea33ec
--- /dev/null
+++ b/frontend-react/src/serviceWorker.js
@@ -0,0 +1,137 @@
+// This code snippet allows you to register a service worker,
+// enabling faster loading and offline capabilities for your app.
+// By default, the registration function is not called.
+
+// While this enhances user experience by enabling quicker loading and
+// offline functionality, it's important to note that developers
+// and users will only see updated content after closing all existing tabs on a page.
+// This is because previously cached resources are updated in the background.
+
+// To understand the advantages of this approach and learn how to opt-in,
+// please refer to our documentation: https://bit.ly/CRA-PWA
+
+const isLocalhost = Boolean(
+ window.location.hostname === 'localhost' ||
+ // [::1] is the IPv6 localhost address.
+ window.location.hostname === '[::1]' ||
+ // 127.0.0.0/8 are considered localhost for IPv4.
+ window.location.hostname.match(
+ /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
+ )
+);
+
+export function register(config) {
+ if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
+ // The URL constructor is available in all browsers that support SW.
+ const publicUrl = new URL(process.env.PUBLIC_URL, window.location.href);
+ if (publicUrl.origin !== window.location.origin) {
+ // Our service worker won't work if PUBLIC_URL is on a different origin
+ // from what our page is served on. This might happen if a CDN is used to
+ // serve assets; see https://github.com/facebook/create-react-app/issues/2374
+ return;
+ }
+
+ window.addEventListener('load', () => {
+ const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
+
+ if (isLocalhost) {
+ // This is running on localhost. Let's check if a service worker still exists or not.
+ checkValidServiceWorker(swUrl, config);
+
+ // Add some additional logging to localhost, pointing developers to the
+ // service worker/PWA documentation.
+ navigator.serviceWorker.ready.then(() => {
+ console.log(
+ 'This web app is being served cache-first by a service ' +
+ 'worker. To learn more, visit https://bit.ly/CRA-PWA'
+ );
+ });
+ } else {
+ // Is not localhost. Just register service worker
+ registerValidSW(swUrl, config);
+ }
+ });
+ }
+}
+
+function registerValidSW(swUrl, config) {
+ navigator.serviceWorker
+ .register(swUrl)
+ .then(registration => {
+ registration.onupdatefound = () => {
+ const installingWorker = registration.installing;
+ if (installingWorker == null) {
+ return;
+ }
+ installingWorker.onstatechange = () => {
+ if (installingWorker.state === 'installed') {
+ if (navigator.serviceWorker.controller) {
+ // At this point, the updated precached content has been fetched,
+ // but the previous service worker will still serve the older
+ // content until all client tabs are closed.
+ console.log(
+ 'New content is available and will be used when all ' +
+ 'tabs for this page are closed. See https://bit.ly/CRA-PWA.'
+ );
+
+ // Execute callback
+ if (config && config.onUpdate) {
+ config.onUpdate(registration);
+ }
+ } else {
+ // At this point, everything has been precached.
+ // It's the perfect time to display a
+ // "Content is cached for offline use." message.
+ console.log('Content is cached for offline use.');
+
+ // Execute callback
+ if (config && config.onSuccess) {
+ config.onSuccess(registration);
+ }
+ }
+ }
+ };
+ };
+ })
+ .catch(error => {
+ console.error('Error during service worker registration:', error);
+ });
+}
+
+function checkValidServiceWorker(swUrl, config) {
+ // Check if the service worker can be found. If it can't reload the page.
+ fetch(swUrl, {
+ headers: { 'Service-Worker': 'script' }
+ })
+ .then(response => {
+ // Ensure service worker exists, and that we really are getting a JS file.
+ const contentType = response.headers.get('content-type');
+ if (
+ response.status === 404 ||
+ (contentType != null && contentType.indexOf('javascript') === -1)
+ ) {
+ // No service worker found. Probably a different app. Reload the page.
+ navigator.serviceWorker.ready.then(registration => {
+ registration.unregister().then(() => {
+ window.location.reload();
+ });
+ });
+ } else {
+ // Service worker found. Proceed as normal.
+ registerValidSW(swUrl, config);
+ }
+ })
+ .catch(() => {
+ console.log(
+ 'No internet connection found. App is running in offline mode.'
+ );
+ });
+}
+
+export function unregister() {
+ if ('serviceWorker' in navigator) {
+ navigator.serviceWorker.ready.then(registration => {
+ registration.unregister();
+ });
+ }
+}
--
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